Roller drum support for a revolver-type gun



J. F. CBRIEN 2,845,006

- July 29, 1958 ROLLER DRUM SUPPORT FOR A REVOLVER-TYPE GUN File'd March12. 1954 2 Sheets-Sheet 1 Wrran NEY5'.

' umszvrok Juhfi III L. O'Brien- July 29, 195 8 J. F. O'BRIEN 2,845,006

' ROLLER DRUM SUPPORT FOR A REVOLVER-TYPE sun Fliled March 12, *1954 2Sheets-Sheet 2 'INZENTQR.

t Jul-1111i. EIEnman ROLLER DRUM SUPPORT FOR A a I v I REVOLVER-TYPE GUN1] J hn F. OBrien, Springfield, Mass., assignor to the United States ofAmerica as represented by the Secretary of the I v Application March 12,1954, Serial No. 415,989

1 Claim. (Cl. 89-155) 7 (Granted under Title 35, U. S. Code (1952), see.266) 1 The invention described herein may be manufactured and used by orfor the Government for governmental purposes withoutthe payment of anyroyalty thereon.

My invention relates to a revolver-type automatic I weapon and moreparticularly to :adevice thereof for supporting a rotatable cartridgedrum.

In the usual weapon including five or six cartridge chambers the drum iskeyed to an axial shaft journaled in the recoil unit of the weapon forrotation of the cham- {bersto stations spaced correspondingly theretoincluding 'a six oclock station of the chambers immediately adja- 7 centthe barrel of the weapon for. firing the cartridges therein. The forwardbearing of the drum shaft, therefore, must be located immediately abovethe barrel and the minimum pitch radius of the chambers equals the sumof the radii of the barrel and the drum shaft plus the thickness of abearing wall therebetween. Hence, the

surface of the drum extends above the remainder of the weapon'and sincethe drum is rotatably mounted, it

. usually overhangs the receiver of the weapon. The diameter ofthe drumtherefore determines the transverse j .silhouette of the weapon.

- In a weapon so arranged, the diameter of the drum is excessive,causing the weapon to present an unnecessarily' large silhouette sincethe thickness of metal between ,five or even six chambers therein ismore than adequate for the strength required to withstand the dischargesof cartridges in the chambers. The silhouette of the weapon canbereduced by reducing the pitch diam- 1 eter of the chambers. t

It is, therefore, an object of my invention to provide a revolver-typeweapon with a low, narrow, transverse.

silhouette.

I Another object of my invention is to provide a weapon .of the kinddescribed having a recoil unit with the car- ,tridge drum thereofrotatable within tangential rollers.

A further object of my invention is to provide the recoilunit of such aweapon with a bearing device for circumferential support of a rotatablecartridge drum.

bearing surfaces for rotation of the cartridge drum in the housing. Afront wall of the housing and a rib of the recoil unit axially positionthe drum.

For a more complete understanding of my invention, attention is directedto the following explanation and the accompanying drawing in which:

- i m ten Fig. 1 isjan elevational view, partly ing sectio .-:,of a

revolver-type automatic weapon incorporating my invention; Figs. 2, 3,linesof Fig. 1;and

Fig. 6 is a perspective view of the drum bearings. V 7

According to the drawing, a revolver-typeweapon 12 includes a receiver14 with a recoil unit 16 slidably disposed thereon, by means of feet '17extending into recesses of the receiver. Recoil unit 16 includes abarrel 18 and a support housing 20 for a drum 22 including chambers 24:and corresponding index rollers 26.

Support 20 is provided with forward and rearward sets of rollers 28journaled on pins 30 secured in bosses 32 of support 20 bymeans ofneedle bearings 34. Drum 22 is provided with a pair of circumferentialbands 36 for tangential engagement with hearing rollers 28 and therollers are disposed to circumferentially restrain the drum v Support 20is relieved by channels'29 in the support.

' to allow insertion of drum'22.

Drum 22 is restrained forwardly and rearwardly, respectively, bya frontwall-38 secured to support 20 by means of bayonet lugs 39 and a stop 40of recoil unit 16. Barrel 18 is threadably secured to a boss 41projecting forwardly from front wall 38. The forward ends l of chambers24 are usually provided with obturating sleeves to prevent escape ofdischarge gases :and, forward wall 38 includes a portion 42 for engagingthe. forward end of drum 22 to retain the sleeves in place duringrotation of the chambers. Portions of the wall may include.

48 secured to a plunger 50 and the cylinder is connected to the bore ofbarrel 18 through a passage 52. An actuator 54 slidable with respect torecoil unit 16 :on feet 55 is biased by springs 56 in engagement with'arear wall 58 of receiver 14 to a battery position in engagement 'with II plunger 50.

Actuator 54 includes surfaces for engagement with index' rollers 26 forreciprocal operation responsive to discharge of firing stationcartridges 45 to serially convey chambers 24 to stations including thefiring station. Gases from the discharge force piston48, plunger 50, andactuator 54 rearwardly against springs 56 to rotate drum-22. When theprojectile from cartridge 45 leaves barrel 18, the pressure on piston 48drops and actuator 54 is returned to the battery position by springs 56aided by the kinetic energy of drum 22.

A shaft 60 is engaged by drum 22 for rotation of a feeder generallyshown at 62.

As shown in Fig. 3, chambers 24 may be disposed in a pitch circle forminimum drum wall thickness therebetween to withstand the force ofdischarge in the firing station. If such a drum-were to be supported bya shaft, the shaft would interfere with barrel 18. However, in thedevice of applicant, the axis of drum 22 coincides with the axis ofsupport 20 and is independent of barrel Reduction of the diameter ofdrum 22 from the drum diameters required in prior weapons, results in adecrease of the transverse silhouette of the weapon that is onlypartially offset by the addition of the drum support.

4 and 5 are .views along the: corresponding recoil unit showing Also,the drum with the reduced diameter requires less energy for rotation andthe weapon is operated with less strain on the component parts.

Although a particular embodiment of the invention has been described indetail herein, it is evident that many variations may be devised withinthe spirit and scope thereof and the following claim is intended toinclude such variations.

I claim:

A revolver-type automatic weapon comprising a barrel, a recoil unit forsupport thereof, a drum having spaced chambers for cartridges, a supportfor said drum secured to said recoil unit, forward and rearward sets ofrollers axially jounaled in said support, and a pair of circumferentialbands on said drum corresponding to said sets of rollers for engagementtherewith for rotational displacement of said chambers.

References Cited in the file of this patent UNITED STATES PATENTS710,723 Smith Oct. 7, 1902 2,434,653 Holschuh et a1 Jan. 20, 1948 02,538,045 Ryan et a1. Jan. 16, 1951 FOREIGN PATENTS 285,180 SwitzerlandDec. 16, 1952 863,614 Germany Jan. 19, 1953

